| Power system including generation,transmission,transform-ation,distribution and other components,Wherein the transmission line as part of a carrier transmission system,It has very important significance to the safe and stable operation of t-he entire power system.After the failure quickly and reliably remove the fault line,and accurately find the point of failure and promptly repair the line,plays an important role in security,stability and economic operation of the entire power system.This paper describes today's major traveling wave fault location method principle at home and abroad,and including single-ended and double-ended fault location method.Systematically compares the advantages and disadvantages of all kinds of traveling wave fault location method.Aiming at the problems of low reliability of positioning of single terminal method,this paper presents a single and double side combination method in traveling wave fault location,the location algorithm with high precision of single terminal method and is not affected by the influence of synchronization error characteristics and continuation of the double terminal method of reliability.And the use of the ratio of positioning calculation,it can eliminate the influence of the length error caused by transmission line.In addition,the paper also describes the principle and detection methods of many kinds of singularity detection methods,and analyzes the advantages and disadvantages of these methods.Aiming at the error of the sampling interval in the traditional singularity detection,this paper proposes a polynomial fitting to the data near the singular point.By calibrating the extreme points on the fitting curve,the mutation point is detected accurately,and the positioning error caused by the sampling rate is eliminated.Based on the ATP platform,the different fault types and fault point of transmission line fault simulation are carried out in this paper,and the 61 sets of transient data are collected.In addition the transient data of PL4 format is converted to mat format by prompt ATP,which can easily be referenced by MATLAB.This paper write a complete fault location matlab program based,which used for the fault location simulation of collected 183 sets of fault data.By comparing the localization results obtained by the traditional detection method and the detection method proposed in this paper are presented,it can be seen that the polynomial fitting method to improve the traditional singularity detection,we can really eliminate due to the sampling rate of positioning error,and can realize fault location whose error is less than 50 m.But when the wavelet transform is used to detect singularity,The simulation results of fault location based on a variety of wavelet bases can be seen,which is affected by the selection of wavelet bases.But if we can choose the suitable wavelet basis for fault analysis,we can get the result of fault location which is close to EMD.According to the simulation results of three kinds of wavelet bases,the positioning results obtained by morl wavelet are the best. |
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